Make It
Step 1
Preheat oven to 350º F. Grease and flour 13 x 9-inch baking pan.
Step 2
Melt 3/4 cup morsels in a small, microwave-safe bowl on HIGH (100%) power for 45 seconds; stir. If necessary, microwave at additional 10- to 15-second intervals, stirring just until smooth. Add coffee granules and ¼ cup evaporated milk; stir well until coffee is completely dissolved. Set aside.
Step 3
Combine nuts, remaining ¼ cup morsels, 1/3 cup sugar and 2 tablespoons butter in medium bowl until crumbly. Set aside.
Step 4
Combine flour, baking soda, salt and baking powder in medium bowl. Beat remaining 1 1/2 cups sugar and remaining 6 tablespoons butter in large mixer bowl until well blended. Beat in sour cream, eggs, remaining 3/4 cup evaporated milk and vanilla extract until blended. Gradually beat in flour mixture. Remove 1 cup of batter and set aside. Stir chocolate mixture into remaining batter. Pour chocolate batter into prepared pan.
Step 5
Drop tablespoons of reserved batter randomly over chocolate batter. Swirl mixture with knife for marbled effect. Sprinkle nut mixture over top.
Step 6
Bake for 38 to 40 minutes or until wooden pick inserted in center comes out clean. Cool completely in pan on wire rack.